Do you have to refrigerate RSO oil?

Quick Answer

RSO (Rick Simpson Oil) can be refrigerated to help preserve potency, but it is not required. RSO is a very stable concentrate that can be stored at room temperature for extended periods without losing potency. Refrigeration may help slow degradation and preserve terpenes.

What is RSO Oil?

RSO, or Rick Simpson Oil, is a highly concentrated cannabis extract made from indica strains. It was pioneered by Canadian medical marijuana activist Rick Simpson and gained popularity as a natural treatment for cancer and other medical conditions.

RSO is made by soaking dried cannabis flower in a solvent like ethanol to extract cannabinoids, terpenes, and other compounds. The solvent is then evaporated, leaving behind a thick, tar-like oil.

Compared to other cannabis extracts, RSO is unique in that:

  • It uses indica strains high in THC
  • No filtering or refinement is done after extraction
  • Resulting oil contains all extracted compounds including fats, lipids, etc.

The lack of filtering gives RSO a tar-like consistency and concentrated flavor. It also means RSO retains a complete cannabinoid and terpene profile with potential therapeutic benefits.

RSO gets its namesake from Rick Simpson, a Canadian engineer who used this type of oil to treat his own skin cancer. He gave the oil away for free to others seeking relief from cancer, chronic pain, and other conditions.

While research is still limited, some studies suggest RSO may help with:

  • Reducing tumor size
  • Killing cancer cells
  • Relieving pain
  • Improving sleep

Today RSO remains popular, especially among medical marijuana patients, for its perceived wellness benefits.

How is RSO Oil Made?

There are a few key steps to making traditional RSO oil:

1. Choose the Cannabis Material

RSO starts with dried cannabis flower that is high in THC. Most recipes call for indica strains as they tend to have the highest THC levels. The THC is believed to be responsible for much of RSO’s therapeutic effects.

Some choose organic cannabis grown without pesticides or chemicals to avoid concentrating any potentially harmful residues in the final oil. Others say the solvent adequately cleans the plant material so this is unnecessary.

2. Grind the Cannabis

The dried cannabis flowers are finely ground to increase surface area for efficient extraction. A grinder, blender, or even mortar and pestle can be used to create a coarse powder.

3. Extract with a Solvent

The ground cannabis is placed in a container and covered with a solvent. Popular options are:

  • 99% isopropyl alcohol
  • Ethanol
  • Naphtha
  • Butane (for BHO extraction)

The container is shaken and stirred periodically to maximize contact between the solvent and plant material. This facilitates the transfer of cannabinoids and other compounds from the plant into the solvent.

4. Drain and Filter the Solvent

After soaking, the liquid solvent is drained and filtered away from the plant material. Cheesecloth or a sieve lined with a filter screen can be used to separate the liquids from the solids.

The solvent will now contain the dissolved trichomes and associated cannabinoids, terpenes, etc. that have been extracted from the initial plant material.

5. Evaporate the Solvent

The filtered solvent is placed in a rice cooker or slow cooker to evaporate away the solvent. Heating should be done carefully to avoid ignition.

As the solvent evaporates, the dissolved cannabis compounds will be left behind in an increasingly viscous residue.

6. Collect the RSO Oil

Once fully evaporated, a thick, molasses-like oil is left. This is raw RSO. It will be potent and often unpleasant tasting.

Some choose to refine the oil further by heating it to decarboxylate THCA into activated THC. The oil can also be diluted using olive oil or flavored concentrates.

How to Store RSO Oil

Raw RSO oil is quite hardy and stable. Its high concentration helps prevent degradation as there are minimal impurities. However, some storage tips can help maximize shelf life:

  • Keep in an airtight container – Exposure to oxygen can accelerate oxidative damage and potency loss.
  • Store away from light – Light can also degrade cannabinoids, especially THC.
  • Refrigerate or freeze – Cooler temperatures slow chemical reactions that cause shelf life decline.
  • Use glass over plastic – Inert glass helps prevent interaction between oil residues and container.

With proper storage techniques, raw RSO oil can retain potency for 6 months or longer at room temperature. Refrigeration extends this further to 1-2 years.

Here are some refrigeration guidelines for maximizing shelf life:

Fridge Storage

Refrigerating RSO oil can effectively double its shelf life compared to room temperature conditions. Keep RSO in an airtight glass container in the refrigerator set to 40°F or below. Avoid the door side which is warmer and opens frequently.

At this chilled temperature, degradation reactions are significantly slowed. Properly refrigerated RSO oil can maintain most of its potency for 12-24 months.

Freezer Storage

For even longer storage, RSO oil can be kept in the freezer at 0°F or colder. Freezing minimizes chemical reactions for maximal preservation.

When freezing RSO, allow some headspace in the container. The oil will expand as it solidifies. Frozen RSO may last 2 years or longer before degrading noticeably.

Thaw frozen RSO in the refrigerator before use. Microwaving or rapid heating can damage oil potency.

Indicators of Bad RSO Oil

With time, RSO oil will slowly oxidize, lose volatile terpenes, and decompose. Signs your refrigerated or frozen RSO has gone bad include:

  • Loss of potency – Less effect from the same dose
  • Change in consistency – From thick and sticky to runny
  • Color changes – From black/brown to orange, yellow, or lighter
  • Terpene loss – Weak smell or taste
  • Separation – Oil separates into layers
  • Foam or bubbles – From decomposition
  • Mold growth – Whitish, fuzzy, or colorful growth

RSO showing any of these changes should be discarded. While not necessarily harmful, degraded oil will have less therapeutic benefits.

Does Refrigerating Change RSO’s Effects?

Refrigerating or freezing RSO oil will not alter its effects or benefits. It simply slows the rate of potency decline over time.

Cooler temperatures reduce decomposition reactions like oxidation, hydrolysis, and loss of volatile compounds. This preserves RSO’s cannabinoid, terpene, and flavonoid profile longer.

However, refrigerating does make the oil thicker and less fluid. Users may need to gently warm refrigerated RSO to make it easier to handle and administer.

Once at body temperature, refrigerated RSO can be consumed normally with no impairment in effects. Any changes would only be noticeable after an extended storage time.

Can You Refrigerate Already Opened RSO Oil?

Absolutely. If using RSO infrequently, refrigerating opened bottles helps preserve freshness between uses.

Leaving RSO oil at room temperature after opening accelerates deterioration from factors like air exposure, light, and warmth.

To maximize shelf life of opened RSO:

  • Store the oil bottle in an airtight container before refrigerating.
  • Ensure the bottle’s own lid/cap is fully sealed.
  • Gently warm refrigerated RSO to make it easier to handle.
  • Use an oven mitt or sleeve when handling cold RSO.
  • Limit the time RSO spends at room temperature.

With refrigeration, opened RSO oil can maintain potency and stability for many months. Just be sure to reseal containers fully between uses.

Does Refrigeration Affect RSO Dosage?

Refrigerating or freezing RSO oil does not directly affect dosage amounts or strength. The cold temperatures simply slow the decline in oil potency over time.

A freshly made batch of RSO oil that is refrigerated immediately will retain near full potency much longer than the same oil left unrefrigerated.

However, an aged batch of RSO oil that has degraded significantly should not be dosed the same as a fresh batch, even if refrigerated. Time still takes a toll.

To summarize:

  • Refrigeration preserves potency but does not increase it.
  • Always start dosing based on oil freshness, not storage method.
  • Adjust dosage down if RSO oil shows signs of aging and degradation.

Proper refrigerated storage maximizes the usable lifespan of RSO oil by slowing potency decline. But inevitable degradation still occurs over years. Dosage should account for age more than temperature.

Is There Any Downside to Refrigerating?

Refrigerating RSO oil has only minimal downsides:


Having to refrigerate and gently warm RSO before each use adds a small chore compared to keeping it at room temperature full-time.

Consistency Changes

Chilled RSO becomes thicker and more viscous. It can be harder to handle and measure dosage amounts. Gently heating refrigerated RSO makes it more fluid.

Humidity Exposure

Repeatedly opening the refrigerator introduces moisture which can very slowly degrade oil over time. Use an airtight container to protect RSO inside a humid fridge.

Overall, the benefits of better preservation greatly outweigh these small negatives. Refrigeration is highly recommended for retaining RSO quality and potency.

Does Refrigeration Affect RSO’s Use in Cooking or Topicals?

Refrigerating RSO oil prior to creating infused products like edibles, tinctures, or topicals has minimal effects.

Any viscosity changes from cold temperature are reversed once RSO is heated during cooking or processing. The RSO integrates seamlessly into the final product.

Likewise, refrigeration has no real impact on topical absorption or efficacy. Once at skin temperature, cold-stored RSO performs the same as fresh RSO in topicals.

The main benefit is starting with fresher RSO that better retains its key compounds thanks to refrigeration. This translates to more potent medicated creations.

Can You Freeze RSO Oil for Even Longer Storage?

Freezing RSO oil is a great option for long-term storage spanning 1-2 years or longer. Freezers below 0°F almost completely halt chemical reactions behind potency loss.

To freeze RSO oil:

  • Fill containers only 3/4 full to allow for expansion.
  • Use airtight glass jars or bottles.
  • Wrap containers in foil to block light.
  • Freeze immediately after making oil.
  • Thaw slowly in the refrigerator before use.

Frozen RSO oil retains maximum cannabinoid and terpene concentrations. It can outlast refrigerated oils by over a year when frozen continuously at 0°F or colder.

Should You Refrigerate RSO Oil?

Refrigerating RSO oil is highly recommended for preserving quality and shelf life. While not mandatory, proper refrigeration provides significant benefits:

  • Slows potency degradation from heat and light
  • Minimizes terpene evaporation and THC breakdown
  • Extends shelf life up to 2 years from 6 months
  • Lets you buy/make RSO in bulk for longer term use
  • Saves money by reducing waste from degradation

For RSO oils used infrequently or stored for more than 2-3 months, refrigeration helps maintain potency and effectiveness. Keep RSO oil airtight and away from humidity to maximize preservation.


While RSO oil does not have to be refrigerated, cold storage is beneficial. Refrigerating at 40°F or below effectively doubles shelf life by slowing potency decline. Freezing offers even longer term storage.

Refrigerated RSO retains higher cannabinoid and terpene concentrations over time. It does not negatively impact effects or usage once warmed to room temperature again. Refrigeration simply makes this potent therapeutic extract last considerably longer.

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